package uk.ac.aber.paws.client.system;


import com.sun.jna.*;
import com.sun.jna.examples.unix.*;

/**
 * @author Rob Johnson, Aberystwyth University
 * @email rob.johnson@aber.ac.uk
 * @date 16th August 2011
 * 
 * MacIdleTime.java
 * 
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

public class MacIdleTime  {

	public interface ApplicationServices extends Library {

		ApplicationServices INSTANCE = (ApplicationServices) Native.loadLibrary("ApplicationServices", ApplicationServices.class);

		int kCGAnyInputEventType = ~0;
		int kCGEventSourceStatePrivate = -1;
		int kCGEventSourceStateCombinedSessionState =0;
		int kCGEventSourceStateHIDSystemState = 1;
	
		/**
		* @see http://developer.apple.com/mac/library/documentation/Carbon/Reference/QuartzEventServicesRef/Reference/reference.html#//apple_ref/c/func/CGEventSourceSecondsSinceLastEventType
		* @param sourceStateId
		* @param eventType
		* @return the elapsed seconds since the last input event
		*/
		public double CGEventSourceSecondsSinceLastEventType (int sourceStateId, int eventType);
	}
	

	public long getIdleTimeMillis() {
		double idleTimeSeconds = ApplicationServices.INSTANCE.CGEventSourceSecondsSinceLastEventType(ApplicationServices.kCGEventSourceStateCombinedSessionState, ApplicationServices.kCGAnyInputEventType);
		return (long) (idleTimeSeconds * 1000);
	}
	
}